Any decent body shop will be able to save the paint. This is what comprehensive insurance is for. Definitely file a police report - if they have this stenciled, it means they do this regularly and when these people eventually get caught this case will add more weight to the sentencing. This is a hate crime.

a little gasoline (seriously) on a rag, and it will wipe right off. Do it at the car wash so you can give the car a good wash right after to get all the gasoline off so it doesn't damage the clear coat.

It will wipe off like it wasn't even there thanks to the clear coat. If it got on some trim pieces (i.e. rubber window surrounds), well that's a different story.